Primary Intraosseous Xanthomas of the Jaws: A Series of Six Cases Including an Example with Formation of Apoptosis-Related Hyaline Globules, So-Called "Thanatosomes"

Primary intraosseous xanthoma of the frontal bone in a child: illustrative case

BACKGROUND

Skull lesions are a common finding in children, with dermoid cysts and eosinophilic granulomas observed most frequently. However, primary intraosseous xanthomas of the calvaria, which are lytic, expansile lesions that develop without underlying hyperlipidemic disease, are rare in children, with only one prior case reported.

OBSERVATIONS

The authors describe the case of a healthy 6-year-old male who presented with a 2-month history of an enlarging midline skull mass that developed after a recent minor trauma. Imaging showed a full-thickness, lytic frontal bone lesion with an aggressive appearance and heterogeneous contrast enhancement. The patient underwent gross-total resection of the lesion with placement of a mesh cranioplasty. Histopathology revealed a primary intraosseous xanthoma. The patient was discharged on postoperative day 2 and required no further treatment at the 1-month follow-up.

LESSONS

This is the first reported case of a primary intraosseous xanthoma in the frontal bone of a pediatric patient. It emphasizes the need to include primary xanthomas in the differential diagnosis for pediatric skull lesions, particularly when the lesion has an aggressive radiographic appearance or the patient has a history of focal trauma. Furthermore, our findings indicate that resection, together with subsequent monitoring for lesion reccurrence, is an adequate first-line treatment.

Xanthoma of the Jaw Bones: Cases Series and Review of Literature

BACKGROUND

Intraosseous xanthomas are rare benign lesions sometimes associated with excess lipid production. Xanthoma of the jaw bones (XJB) was first reported in 1964, and fewer than 50 cases have been reported in the English literature to date. The etiopathogenesis of XJB is highly suggestive of a reactive process or a metabolic condition.

METHOD

Seven cases of XJBs were retrieved from the archives of 4 oral and maxillofacial pathology services. Clinical, radiographic and histopathologic features of all these cases were retrospectively analyzed. Immunohistochemical (IHC) stains for S100 and CD68 were performed.

RESULTS

All seven cases involved the mandible. Patients' age ranged between 13 and 69 years with an evenly distributed female to male ratio. One patient had a medical history of hyperlipidemia, but the medical and dental histories of the others were unremarkable. For most cases, XJB was an incidental finding discovered during routine radiographic examination. Swelling and cortical expansion were noted in a few cases. Radiographically, cases typically presented as either well-defined multilocular or unilocular lesions, which were either radiolucent or mixed radiolucent/radiopaque. All the lesions were treated with surgical curettage and no recurrence was observed during subsequent follow-ups. Each of the seven cases exhibited sheets of foamy macrophages. The diagnosis is established by exclusion of entities with overlapping microscopic features and involved correlation with the clinical, histological, radiographic and IHC profiles. Immunohistochemically, all the cases expressed diffuse positivity for CD68 and were negative for S100.

CONCLUSION

XJB is a rare lesion of unknown etiology, which may mimic other benign or reactive jaw lesions. Due to its rarity and the potential diagnostic challenges it presents, clinicians must remain vigilant and consider CXJ in their differential when assessing radiolucent jaw anomalies.

Signet-ring cell sinus histiocytosis: report of the clinicopathologic characteristics of 4 cases with emphasis on the differential diagnosis of signet-ring cell lesions

Signet-ring cell sinus histiocytosis (SRCSH) represents a distinctly rare reactive phenomenon predominantly affecting axillary and pelvic lymph nodes (LNs) of individuals with breast or prostatic adenocarcinoma. Reports of SRCSH in the literature are sparse with only 12 previous examples, thus underscoring the rarity of this process. Here, we report 4 additional SRCSH cases affecting 2 women and 2 men (M/F = 1:1; age range: 50-71 years; mean age = 61 years). In the 2 men, pelvic LNs were excised during radical cystoprostatectomy for genitourinary cancer, whereas in one woman, SRCSH was incidentally discovered in axillary LNs during mastectomy for breast adenocarcinoma. The other female patient presented with a history of aortic valve replacement and enlarged supraclavicular LNs. Microscopically, all involved LNs exhibited marked distention with filling of the subcapsular and medullary sinuses by sheets of signet-ring histiocytes containing a singular large, cytoplasmic vacuole and a crescentic nucleus. Overt cytologic atypia, pleomorphism, and mitoses were absent. Erythrophagocytosis and occasional fibrosis were appreciated. None of the LNs with SRCSH showed evidence of metastatic tumor. Immunohistochemically, signet-ring sinus histiocytes were invariably positive for CD68 and CD163 but were negative for pancytokeratins. The histopathologic characteristics of SRCSH, albeit bland, in conjunction with the patient's medical history, may be misinterpreted as metastatic adenocarcinoma with signet-ring cell configuration. Immunohistochemical confirmation of the histiocytic lineage of the lesional cells in SRCSH usually suffices for rendering an accurate diagnosis. The underlying pathogenetic mechanism and possible biologic significance of SRCSH remain currently unknown.

Benign fibrohistiocytic jaw lesions: a 48-year clinicopathologic analysis and review of the literature

OBJECTIVE

Intra-osseous fibrohistiocytic lesions have long been reported in the literature; evidence suggests they represent a heterogeneous group of reactive and neoplastic processes. This study evaluated a series of gnathic fibrohistiocytic lesions to identify and categorize their clinical, radiographic and morphologic spectrum.

STUDY DESIGN

A retrospective case search over 48 years was conducted for maxillary and mandibular intra-bony fibrohistiocytic lesions. Diagnoses were confirmed and demographic, radiographic, clinical and follow-up data was analyzed.

RESULTS

Fifty cases met the inclusion criteria. Most cases (80%) were found in the second through fourth decades (mean, 29 years). The most common location (86%) was the posterior mandible. Radiographic presentations varied, but a few patterns emerged, including a distinctive mottled, honeycomb type with punctate lucencies. All cases demonstrated fibrous components admixed with variable histiocytes. Eight cases (16%) were histiocyte-rich with dominant sheets of xanthoma cells. Immunohistochemical staining revealed strong CD68 and CD163 expression, along with variable smooth muscle actin staining. The vast majority (92%) of cases were treated conservatively. Available follow-up showed lesional stability in 17 cases (average, 85 months) with 2 recurrences (24 months each) and no evidence of malignant transformation.

CONCLUSIONS

This study is the largest to date of fibrohistiocytic gnathic lesions, revealing distinctive radiographic and histologic findings and characteristic clinical and immunophenotypic features. Available evidence suggests that most of these are indolent, slow-growing lesions amenable to conservative therapy.

Primary Mandibular Condyle Xanthoma: Case Report and Literature Review

Bone xanthoma is a rare benign primary bone lesion histologically characterized by sheets of foamy cells which are macrophages with a cytoplasm filled with droplets of fat. It is usually associated with endocrine or metabolic diseases, in the absence of which the lesion is called primary xanthoma. Because of the lack of pathognomonic radiologic and clinical features, they require a differential diagnosis with a broad spectrum of lesions with a varying degree of malignant potential. We describe a case of primary mandibular xanthoma of a 16-year-old girl without typical cutaneous manifestations and alterations in lipid values. The temporomandibular joint involvement at the mandibular condyle is peculiar in the case described here. We present even a qualitative systematic review of the literature on primary xanthoma of the jaws in others to draw up treatment guidelines.

Clinical and pathological studies of eight cases of lipidized fibrous histiocytoma

Lipidized fibrous histiocytoma (FH) is a rare type of FH. The present study aimed to describe the clinical and pathological features of lipidized FH. A total of eight patients diagnosed with lipidized FH were retrospectively reviewed in the present study. The cohort included three male and five female patients (male to female ratio, 1.7:1) with a mean age of 48 years (range, 38-62 years). In total, four tumors were located on the buttock, three on the lower leg and one on the forearm. Histological, lipidized FH showed a wide spectrum. Some cases included prominent stromal hyalinization and hyalinized vessels with scant lipid-laden histiocytes. Other cases exhibited the prominent lipid-laden histiocytes and scant stromal hyalinization. Overall, lipidized FH must be differentiated from other benign and malignant tumors, taking into account the therapeutic and prognostic differences between these different entities.

Primary xanthoma inferior to the right mandibular third molar and intraoral vertical ramus osteotomy

Intraosseous xanthoma of the mandible is a rare benign disorder. A 17-year-old male patient presented with a suspected abscess in the right mandibular third molar, detected on a panoramic radiograph. The patient had no history of systemic or lipid-related metabolic diseases and complained of no specific symptoms or pain. A radiographic examination revealed a heterogeneous radiolucency extending from the apical to the distal aspect of the right mandibular third molar tooth germ. The lesion measured 9×16×24 mm (antero-posterior×mediolateral×supero-inferior) and showed a relatively well-defined, multilocular, foamy appearance with hyperostotic borders spreading to the inferior alveolar nerve canal. After excisional biopsy, a diagnosis of central xanthoma was made. The lesion recurred, and intraoral vertical ramus osteotomy was done near the lesion. For the treatment of xanthoma of the mandible, extensive and delicate surgical treatment under general anesthesia should be considered.